Dial lock for automatic telephones



April 3, 192s. 1,664,939

L. F. MORTIMER DIAL LOCK FOR AUTOMATIC TELEPHONES Filed Deo. 31, 1925 Patented Apr. 3, 1928.

UNITED STATES PATENT OFFICE.

LEWIS F. MOBTIMB, 0F LG-S'ANGELES, CALIFORNIA.

nur. Loox Eon AUTOMATIC: '.rELErHoNEs.

Application mea December a1, 1925. sera-.11m rasee.

My invention relates generally to televenting the unauthorized use of thetelc phones for outgoing calls.

Further objects of my invention areto provide a. dial lock of the character referred to that' is relatively simple in construction, capable of Vbeing easily and cheaply produced, and which will be very eective in performin its intended functions.

l It will ge understood that in practically al1 large telephone exchanges now in operation, the majority of the telephones are leased or supplied to the subscribers on a metered service plan, that is, a fixed charge for each outgoing call. Where such service is -in vogue, it is diiicult for the subscriber to prevent the unauthorized useof his telephone, and it is the urpose of my invention to provide relative y simple dial locking `means that may be easily and quickly applied to or removed from the calling dial portion of an automatic telephone and which will be effective in preventing anyone except the subscriber or holder of the key of the locking device from actuating the dial to make a call.

With the foregoing and other objects in view, my invention consistsfin certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawings in whichz` Fig. 1 is a perspective view of a dial locking plate of my improved construction.

Fig. 2 is a top plan view -of the base portion of an automatic telephone and showing my improved locking device in position on the rotary calling dial. y Fig. 3 is a side elevational view of the base portion of an automatic telephone and showing the locking plate in position on the dial thereof.

Fig. is an enlar ed cross section taken on the 11ne7'7 of ig. 6.

Fig-8 is a top plan view of a further 'modified form of the dial lock.

Fig. 9 is an enlarged cross section taken yapproximately on the line 9-9 of Fig.v v8.

Referring hy numerals to the accompanying drawings which illustrate afpractical embodiment of my invention, and particularly to the form of device illustrated in Figs. 1, 2, and 3, 10 designatesthe base portion of a desk tele hone instrument of the automatic dial calling type, 11 the post or standard that supports `the transmitter and receiver and 12 the circular base upon which 1s mounted for rotation the dial 13 having the yfinger tip openings 14.

Secured' in the usual manner by screws 15 to the side of the circular base 12 is an up wardly and inwardly projecting hook 16, the upper portion of which overlies the perforated marginal portion of the dial 13 and' co-l nsv

serving as a stop for the finger while the l dial plate is being rotated in making a call.

The locking means contemplated by my invention comprises an arcuate plate 17 that is adapted to overlie a portion of dial-13, and formed' in said 'plate near one end thereof is an aperture 18 that is adapted to coin cide with one of the apertures 14 in the dial. A portion of the material forming plate 17 is pressed upwardly at `the inner end of the perforations 18 to provide a horizontally disposed -lip ory nger 19, which, when the device is` applied forI use, overlies hook or finger sto 16. .l

Forme integral with the outer edge of arcuate plate 17 and depending therefrom is a curved plate 20 that is, adapted to overlie a portion of the edge of the circular base 12 and particularly that portion to which the base of hook 16 is secured.

When the latching late constructed as just 'described is -apphed' to the dial, the f hook or finger 19 occupies a position over the hook 16 and depending plate 20 overlies the hase ortion of said hook 16 as illus trated in ilTigs. 2 and 3. The locking plate is locked to the perforated dial by the shackle portion of a small padlock P, and which shackle portion passes 'through apertue 18 and one of the apertures 14 in said dial. With the plate locked to the dial as through the aligned perforations 25 and 28.`

just described, it will be impossible to rotate the dial to the' proper successive positions `to complete the call, inasmuch as a substantial .portion of the plate 17 is ositioned in front'of the Stop hook 16'an as plate 2O 'covers the hase portion of the hook 16, it will be impossible for the screws 15 that secure the hook 16 to base 12 to be removed, in which latter event it might be possible to rotate the perforated dial-with the locking plate screwed thereto into the positions necessary to make a call. v

Obviously the subscriber of the telephone or some authorized person holds the key or keys to the padlock and when the latter is unlocked and the shackle disengaged from the dialand perforation 18, the locking plate may be very easily and quickly removed so as to permit the dial to be used in the ordinary manner.

In the modified form of locking device illustratedin Fig. 4 and 5, a straight bar 21, preferably of metal, has one end bent down- .wardly -so as to engage through one of the perforations in the dial when bar 21 is, arranged, diametrically on top of said dial and the opposite end of bar 21 is bent downward to form an L-shaped member 22, the verti cal leg of which is'adapted to overlie the vertical portion 'of stop hook 16. .1 j

Depending from bar 21 is a pin 23 that-is adapted to pass through one of the apertures in the dial and when the locking bar is properly arranged `for use, the shackle of a padlock passes around the vertical leg of. the L-shaped member and the adjacent vertical leg of the stop hook 16.

In the modified construction illustrated in Figs. 6 and 7, atop plate 24 is` provided adjacent to one end with a perforation 25 and depending from the other end of said `plateis a stud 26 from the lower portion of which projects outwardly a narrow plate 27 that. lies parallel lwith plate 24 and said plate 27 being provided with a perforation 28 that is in vertical alignment with perforation 25. When this locking device is applied for use plate 27 and stud 26 are inserted through one of the perforations in the dial and the shackle of a padlock passes When'thus locked to the dial, itfunctionsas av stud to engage lingers 16 thereby limiting Per the rotary motion that may be imparted to the calling dial.

In the modiied construction illustrated in Figs. 8 and 9, a base plate 29 has secured thereto a pair of' pins 30 that extend upwardly through apertures formed in an upplate 31 and said pins pass into the body of a padlock 32 which latter is secured "to said top plate 31. As a result of this arrangement, the plates 29 and 31 may move away from each other when the padlock is unlocked and into position vadjacent to each relatively simple, practical `and effective means for locking the dial plate of an automatic .telephone and consequently` preventing the unauthorized use of said telephone.

It will be understood that minor changes in the size, form and construction of the va-y rious parts of my improved lock may be made 'and substituted for those herein shown and described without departing from the spirit of my invention, thescope' of which is set forth in the appended claims.

I claim as my invention: l

1. .The combination with an automatic telephone, its rotary dial' and finger stop hoo and' is substantially L-shape in cross section so that it will overlie -a portion of the top and edge of the rotary dial of the telephone and which plate is rovided with an aperture that is adapted to coincide with one ofthe apertures -in the dial and receive `a ydetachable locking device.

2. The combination with an automatic telephone, its rotary dial `and 'finger stop hoo of a plate adapted to overlie a portion of the rotary dial, which plate bein provided with an aperture that is adap d to coincide with. one of the apertures in the dial and receive a detachable lookin device and a finger carried b said` late, w ich in' with an aperture that is a apted'to coincide with one of the lapertures 1n the ydial and.

receive a detachable locking device and a plate depending from the outer edge of the first-mentioned late and adapted when the device is ap lie .for use to overlie the base portion of t e finger stop hook.

4. The combination Awith an automatic telephone, its rotary dial and finger stop hoo of a plate adapted-to overlie a portion of the rotary dial, which plate is provided with an aperture ythat is adapted to coincide with one ofthe apertures in the'dial and receive a detachable locking device, a finger carried by said plate, which finger -is-adapted to overlie the finger stop hook andaplatc depending from the outer edge of the iirstmentioned plate and adapted when the de vice is applied for use to overlie the base portion of the finger stop hook. I

5. A dial lock for automatic telephones comprising a plate provided adjacent to one of a plate that is curved lengthwise,

lll!

end with an aperture, a inger projecting from said plate at one end of'said aperture and a plate projecting from one edge of the first mentioned plate and arranged substantially at right angles thereto.

6. In a dial lock for automatic telephones, an inverted L-shaped member that is curved lengthwise, there being an aperture formed near one end of saidmember, which aperture is adapted to receive a part. of a locking device and a inger projecting from said member adjacent to the aperture therein.

7. The combination with an automatic telephone and its rotary dial plate, of an inverted L-shaped member adapted to overlie a portion of the top and edge of the dial plate of the telephone and said L-,shaped member being provided with an aperture that is adapted to coincide with one of the apertures in the dial plate and to receive a 20 part of a locking device.

In testimony whereof I aix my signature.

LEWIS F. MORTIMER. 

